U.S. patent application number 09/783365 was filed with the patent office on 2002-08-15 for methods and apparatus for an electronic shelf label communication system.
This patent application is currently assigned to NCR Corporation. Invention is credited to Otto, Jerome A..
Application Number | 20020109603 09/783365 |
Document ID | / |
Family ID | 25129019 |
Filed Date | 2002-08-15 |
United States Patent
Application |
20020109603 |
Kind Code |
A1 |
Otto, Jerome A. |
August 15, 2002 |
Methods and apparatus for an electronic shelf label communication
system
Abstract
Techniques for an electronic shelf label (ESL) system which uses
an ESL's liquid crystal display (LCD) to transmit information to a
relay unit, or CBS, by reflecting infrared (IR) or visible light to
the relay unit. In a first embodiment, a plurality of IR light
sources flood the area where the ESL is located. To transmit a
message to the relay unit, the ESL reflectively modulates the IR
light by blinking, or turning on and off, at least one segment of
the LCD display. The relay unit then receives and interprets the
modulated reflected IR light. In a second embodiment, the relay
unit does not generate IR light. Instead, the ESL reflectively
modulates the visible light present in the retail establishment to
transmit a message to the relay unit. The relay unit may use one or
more cameras to receive this reflectively modulated visible
light.
Inventors: |
Otto, Jerome A.;
(Centerville, OH) |
Correspondence
Address: |
Paul W. Martin
NCR Corporation
Law Department
101 W. Schantz Avenue
Dayton
OH
45479
US
|
Assignee: |
NCR Corporation
|
Family ID: |
25129019 |
Appl. No.: |
09/783365 |
Filed: |
February 14, 2001 |
Current U.S.
Class: |
340/691.6 ;
340/691.1 |
Current CPC
Class: |
G06Q 30/06 20130101;
G06F 3/147 20130101; H04B 10/114 20130101; Y02A 10/46 20180101;
Y02A 10/40 20180101; G09G 2380/04 20130101 |
Class at
Publication: |
340/691.6 ;
340/691.1 |
International
Class: |
G08B 003/00 |
Claims
I claim:
1. An electronic price label (ESL) system comprising: an infrared
(IR) light source for generating IR light; an ESL for reflectively
modulating the IR light to transmit a message; and an IR receiver
for receiving the reflectively modulated message.
2. The ESL system of claim 1 wherein the ESL comprises a display
having at least one display segment and the ESL reflectively
modulates the IR light by blinking the at least one display
segment.
3. The ESL system of claim 2 wherein the display is a liquid
crystal display.
4. The ESL system of claim 2 wherein the display is for displaying
information relating to an item offered for sale.
5. The ESL system of claim 2 wherein the at least one segment
displays information relating to an item offered for sale.
6. The ESL system of claim 1 wherein the at least one display
segment blinks at a rate of at least 30 cycles per second.
7. The ESL system of claim 1 wherein the ESL is for transmitting
the message in response to command transmitted from a host
system.
8. An electronic price label (ESL) comprising: a receiver for
receiving a message; and a display for reflectively modulating
incident light to transmit a response to the message.
9. The ESL of claim 8 wherein the incident light is infrared
light.
10. The ESL of claim 8 wherein the incident light is visible
light.
11. The ESL of claim 8 wherein the display has at least one display
segment and the ESL reflectively modulates the incident light by
blinking the at least one display segment.
12. The ESL of claim 8 wherein the display is for displaying price
information of an item.
13. The ESL of claim 8 wherein the display is a liquid crystal
display.
14. An electronic shelf label communication method comprising the
steps of: (a) generating infrared (IR) light by an IR light source;
(b) reflectively modulating the IR light by an ESL to transmit a
message; and (c) receiving the reflectively modulated IR light by a
receiver.
15. The method of claim 14 further comprising the step of:
interpreting the reflectively modulated light to decode the
message.
16. The method of claim 14 wherein the ESL includes a display and
wherein step (b) further comprises the substep of: repetitively
turning on and turning off a segment of the display.
17. The method of claim 16 wherein the display is a liquid crystal
display.
18. The method of claim 14 further comprising the step of
transmitting a signal to the ESL and wherein the message is
transmitted in response to the signal.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to improvements in
electronic shelf label (ESL) systems used in transaction
establishments. More specifically, the present invention relates to
advantageous aspects of a wireless ESL communication system.
BACKGROUND OF THE INVENTION
[0002] ESL systems typically include a plurality of ESLs for each
merchandise item in a store. ESLs display the price of
corresponding merchandise items on store shelves and are typically
attached to a rail along the leading edge of the shelves. A store
may contain thousands of ESLs to display the prices of the
merchandise items. The ESLs are coupled to a central server where
information about the ESLs is typically maintained in an ESL data
file which contains ESL identification information and ESL
merchandise item information. Price information displayed by the
ESLs is obtained from a price look-up (PLU) data file. The central
server sends messages, including price change messages, to the ESLs
through a communication base station (CBS) which may be mounted in
the ceiling of the retail establishment.
[0003] The communications link from the CBS to an ESL, known as the
"downlink", uses infrared (IR) or radio frequency (RF) technology.
To ensure that a message transmitted to the ESL was properly
received, the ESL transmits a positive acknowledgement over an
"uplink" communication path to the CBS, which in turn relays the
acknowledgment to the central server. The downlink communications
path is separate from and may employ different technology than the
uplink communication path, since the uplink path transmits much
less data than the downlink path. For example, the ESL may transmit
an acknowledgement which consists of a single status byte.
[0004] Not only is it important for the communication links to be
reliable, but for ESL systems to be cost effective, ESLs must be
inexpensive and the cost of the infrastructure, such as the CBS,
kept to a minimum. Since the downlink is transmitted from the CBS
which may be operated by an external power source, providing
transmission power for the downlink is not usually a concern.
However, the uplink signal is originated by the ESL, which is
typically powered by a battery. Since battery life of the ESL is an
important design consideration, utilizing an active uplink which
actively transmits an RF or IR signal may consume excessive power
and reduce battery life.
[0005] Thus, it would be desirable to provide a reliable uplink
communication path for an ESL system which consumes minimal battery
power while providing a large communication range.
SUMMARY OF THE INVENTION
[0006] The present invention advantageously provides methods and
apparatus for an ESL system which uses the ESL's liquid crystal
display (LCD) to transmit information to a relay unit, or CBS, by
reflecting infrared (IR) or visible light to the relay unit. In a
first embodiment, a plurality of IR light sources flood the area
where the ESL is located. To transmit a message to the relay unit,
the ESL reflectively modulates the IR light by blinking, or turning
on and off, at least one segment of the LCD display. The relay unit
then receives and interprets the modulated reflected IR light. In a
second embodiment, the relay unit does not generate IR light.
Instead, the ESL reflectively modulates the visible light present
in the retail establishment to transmit a message to the relay
unit. The relay unit may use one or more cameras to receive this
reflectively modulated visible light.
[0007] A more complete understanding of the present invention, as
well as further features and advantages of the invention, will be
apparent from the following detailed description and the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a block diagram of a transaction management system
in accordance with the present invention;
[0009] FIG. 2 is a block diagram of an ESL in accordance with the
present invention;
[0010] FIG. 3 is a block diagram of a relay unit in accordance with
the present invention;
[0011] FIG. 4 is a frontal view of an ESL in accordance with the
present invention; and
[0012] FIG. 5 shows a method of communicating with an ESL in
accordance with the present invention.
DETAILED DESCRIPTION
[0013] The present invention now will be described more fully with
reference to the accompanying drawings, in which several presently
preferred embodiments of the invention are shown. This invention
may, however, be embodied in various forms and should not be
construed as limited to the embodiments set forth herein. Rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art.
[0014] FIG. 1 shows a transaction management system 100 in
accordance with the present invention. The system 100 includes a
host computer system 102 and a point-of-service (POS) system 104.
Here, components 102 and 104 are shown as separate components that
are networked together, but they and their subcomponents may also
be combined or divided in various ways. Thus, host computer system
102 may be a POS terminal which doubles as a host computer for a
network of other POS terminals.
[0015] The host computer system 102 includes a storage medium 106,
system software 108, ESL software 110, a display 112 and an input
device 114. The storage medium 106 includes a PLU data file 107
which stores item prices which are available for distribution to a
POS terminal 116 by the host system 102. Alternatively, provision
may be made for a bar code scanner 118 to directly access the PLU
data file 107. The storage medium 106 also includes ESL data file
109 which contains item information, such as a PLU number and ESL
identification information for each of the ESLs 122. The system 102
executes system software 108 which updates the contents of storage
medium 106 and performs other system functions, as described in
greater detail below. Input device 114 is preferably a keyboard,
but it will be recognized that data can be entered in a variety of
alternative manners.
[0016] POS system 104 includes bar code scanner 118 and POS
terminal 116.
[0017] The system 100 also includes relay units 120 and ESLs 122.
The relay units 120 may be suitably mounted in or near the ceiling
of the retail establishment.
[0018] ESL software 110 records, schedules, and transmits all
messages to ESLs 122. ESL software 110 controls the transmission of
messages, including price change messages, to ESLs 122 utilizing
relay units 120 which are placed periodically across a retail
establishment. These messages are sent to the relay array units 120
through communications link 124. Communications link 124 may
suitably utilize radio frequency (RF) communication, infrared (IR)
communication, a wired link, or some combination of communication
techniques. After receiving a message from the host system 102, the
relay units 120 then transmit the message to the ESLs 122 utilizing
a further communications link 126, which may suitably utilize RF
communication, IR communication, a wired link or some combination
of communication techniques. In an alternate embodiment, host
system 102 may communicate directly with ESLs 122.
[0019] After receiving a message, the ESLs 122 may respond with an
acknowledgement which is transmitted to the relay units 120 over
communication link 127, as described in greater detail below. The
relay units 120 would then retransmit the acknowledgement message
to the host system 102 over communication link 124.
[0020] FIG. 2 shows a block diagram of the ESL 122 in accordance
with the present invention. A liquid crystal display (LCD) 202
displays information, such as item price and related data. ESL 122
includes a receiver 206 for receiving messages from the relay unit
120. The receiver may utilize RF communication, IR communication, a
wired link or some combination of communication techniques. A power
source 208 provides power for the operation of ESL 122. The
operation of ESL 122 is controlled by ESL circuitry 204 which
decodes incoming messages received and performs any actions
indicated by the messages. For example, if a price change message
is received, the ESL circuitry 204 would cause the display 202 to
be updated with the new price information. Volatile RAM 210 stores
the ESL identification number and the displayed message. ESL
circuitry 204 may also include a variety of components such as
timers and other electronic components.
[0021] FIG. 3 shows a block diagram of the relay unit 120 in
accordance with the present invention. A host communication system
302 provides an interface to the host system 102. Messages to the
ESLs 122 are transmitted by an ESL transmission system 304 over the
communications link 126, as described above. An infrared (IR)
source 306 generates infrared light which is used to flood an area
containing ESLs with IR light. A plurality of ESL IR receivers
308a, . . . ,308n receive and interpret the infrared light which
has been reflected by an ESL 122. While the relay unit 120 is shown
as a single device for ease of illustration, as would be understood
by one skilled in the art, the present invention is not so limited
and may be implemented as separate units.
[0022] After receiving a message transmitted from the relay unit
120, the ESL 122 responds by sending an acknowledgement message to
the relay unit 120. The ESL 122 reflects and modulates the IR light
transmitted from the relay unit 120. In a preferred embodiment, the
ESL 122 modulates the IR light by blinking a special segment 402 of
the LCD display 202, as shown in FIG. 4. In another aspect, the ESL
122 blinks some or all of the segments 404 which are used to
display information. The blinking of a display segment varies the
reflectivity of the segment with respect to IR light, thus varying
the IR light which is reflected from the display. Such blinking may
advantageously occur at a frequency at or above 30 cycles per
second in order to prevent the blinking from being visible to a
customer in the retail establishment. Since the IR light is
reflected off many surfaces in the retail establishment, the EPL
122 does not need to be located in a direct line of sight from the
relay unit 120.
[0023] In an alternate embodiment of the present invention, the
relay unit 120 does not flood the retail establishment with IR
light. Instead, the ESL 122 reflectively modulates visible light to
transmit a message or response to the relay unit 120 which may use
a camera or other suitable optical receiver to receive the
message.
[0024] FIG. 5 shows a method 500 of communicating with an ESL in
accordance with the present invention. In step 502, an ESL, such as
ESL 122, receives a message from a relay unit. In step 504, an
infrared (IR) light source, such as IR source 306, floods the ESL
with IR light. In step 506, the ESL responds to the message by
reflectively modulating the IR light. In a preferred embodiment,
the ESL reflectively modulates the IR light by blinking, or
repetitively turning on and off, at least one segment of the ESL's
liquid crystal display (LCD). In step 508, an IR receiver, such as
ESL IR receiver 308a, receives the reflectively modulated IR light
and interprets the message.
[0025] It will be apparent to those skilled in the art that various
modifications and variations can be made in the present invention
without departing from the spirit and scope of the present
invention. Thus, it is intended that the present invention cover
the modifications and variations of this invention provided they
come within the scope of the appended claims and their
equivalents.
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